The Chandrayaan-3 mission marked a significant milestone in lunar exploration with its Chandra’s Surface Thermophysical Experiment (ChaSTE) onboard the Vikram lander. ChaSTE became the first instrument to measure temperature variations in situ near the Moon’s south pole.

Using a thermal probe equipped with 10 sensors spaced 1 cm apart, it successfully penetrated 10 cm into the lunar soil, collecting data on temperature profiles during its operational period from August 23 to September 2, 2023.

The ChaSTE (Chandra's Surface Thermophysical Experiment) payload onboard Chandrayaan-3's Vikram lander is designed to study the thermal properties of the lunar surface, particularly at the Moon's south pole. The probe features 10 temperature sensors spaced approximately 1 cm apart along its length, near the nose-tip.

It employs a rotation-based deployment mechanism where a motor rotates to push the probe needle downward until its tip touches the lunar surface. Scientists monitor the temperature readings from the sensor at the tip to confirm contact with the surface. As the probe penetrates deeper into the lunar soil, increasing resistance from the Regolith requires greater force from the motor, enabling scientists to measure penetration depth.

The probe can reach up to 10 cm beneath the surface, providing critical data on temperature variations and thermal conductivity at different depths.

This experiment marks the first-ever in-situ temperature profile of the lunar south pole, contributing valuable insights into its thermal behaviour and aiding future lunar exploration efforts.

ChaSTE revealed sharp temperature variations, with surface temperatures reaching up to 45°C and dropping steeply to -10°C just 10 cm below the surface. This data is crucial for understanding the thermal behavior of the lunar soil and assessing the prevalence of water ice in the region.

Unlike previous missions such as ESA's Philae lander and NASA's InSight spacecraft, which faced deployment challenges due to hammering mechanisms, ChaSTE utilised a rotation-based deployment system that ensured successful soil penetration and data collection.

This achievement highlights India's pioneering role in lunar south pole exploration, providing valuable insights into the Moon's thermal environment and its potential resources for future space missions.

Agencies